    function onClick() {
        alert("按钮被点击");
    }
    const user = {
        name: 'Hedy Lamarr',
        imageUrl: 'https://i.imgur.com/yXOvdOSs.jpg',
        imageSize: 90,
    };

    export default  function MyApp() {
        return <>
            <h1>Hello, world!</h1>
            <button onClick={onClick}>clickme</button>
            <h1>{user.name}</h1>
            <img
                className="avatar"
                src={user.imageUrl}
                alt={'Photo of ' + user.name}
                style={{
                    width: user.imageSize,
                    height: user.imageSize
                }}

                />
        </>
    }

